As restless as humans, Bay Area mountain lions have commute patterns just like ours. A new research project is identifying where humans and pumas cross paths, in hopes of preventing deadly consequences.

Seven of these powerful, elusive and elegant animals — separated by Highway 17 — wear satellite-connected radio collars, allowing University of California-Santa Cruz scientists to reliably plot their numerous routes and spy on the cats on Web cameras.

Preliminary data show the cats prefer remote territories, but routinely skirt the edges of active neighborhoods to get from one piece of wilderness to another.

One of the studied cats often crosses Bonny Doon Road; another prowls near east Los Gatos. A third was documented traveling within one-third of a mile from San Jose’s Almaden Golf Course and the Graystone and Orchard Creek subdivisions.

This pioneering study is generating unprecedented insights into the range and behaviors of these poorly understood animals. Well-muscled, mountain lions range from 7 to 8 feet in length and weigh as much as 300 pounds. They create deep anxiety among hikers and homeowners but pose little real threat. One recent casualty was a Chihuahua outside Watsonville.

Dangerous crossings

Since last fall, the UC-Santa Cruz team has hiked the mountains in search of the cats, using traps to capture, tranquilize and collar them. On each collar is a GPS device that records the cat’s location, and an accelerometer to measure every activity — running, standing, even drinking water.

“It shows that they know where the humans are, and try to avoid them,” said lead investigator Chris Wilmers, who has collected a year’s worth of data for the Santa Cruz Puma Project.

About 25 cats live in this region of the Santa Cruz Mountains. About 5,000 are thought to live in California, increasingly hemmed in by subdivisions.

“For the most part, they travel where they can be least seen,” said Wilmers, assistant professor in UCSC’s Department of Environmental Studies. Blonde and laconic, he climbs the rugged mountains with hound dogs in search of the giant cats.

But no matter how cunning and strong, they face formidable obstacles. One is busy Highway 17, which bisects the Santa Cruz Mountains, where a cat was struck and presumed killed by a car in July 2008.

“If we want the mountain lion to survive, given all the development occurring in the area, where are the important habitats and corridors?” asked Wilmers.

“How are they getting across Highway 17? How are they getting across Highway 92, or Highway 101? For that matter, how do they get from the Santa Cruz Mountains to the Diablo Range, or the Gavilan Mountains, or the Santa Lucia Mountains?”

Tracking travel

In addition to the seven collared adult cats — three males and four females — the team hopes to track the route of a young collared male. He is one of three newborns that arrived in spring near the headwaters of Little Creek. As the young cats mature, they may travel great distances to establish new ranges, far from their families.

The fate of an eight-year-old male cat whose vast range spread from Lexington Reservoir to Uvas Reservoir, is also a concern.

“We suspect it was killed. Either it was run over on a road, or died in a deep canyon so is no longer sending a signal. Or someone shot it, and kept the collar.”

The study’s goal is to provide data for conservation planning and study how lions travel, use wildlife corridors and coexist with people in a rapidly urbanizing region. Someday, said Wilmers, it may be possible to build routes between habitats — offering alternatives to crossing deadly highways.

Deer for dinner

On the Peninsula, there have been so many recent sightings that the region is beginning to resemble the Great Cats exhibit at the zoo. But none of the lions there are part of the Santa Cruz Puma Project. Plans for a Palo Alto-based research project were abandoned several years ago due to lack of staff.

Perhaps that was not a good idea.

In 2004, police shot and killed a young mountain lion who was treed near Palo Alto’s Rinconada Park near two schools.

Another was spotted Sept. 28, off Edgewood Drive — not up in the foothills, but near the San Francisquito Creek and Highway 101.

“We sure wish we knew where they were, and how many there are,” said Palo Alto naturalist Deborah Bartens.

The cameras and radio collars on the Santa Cruz cats allow the biologists to accumulate a trove of information about other behaviors.

For instance, they’ve learned that deer are their favorite prey; occasionally, they’ll eat pigs and raccoons and skunks. The beavers who live in Los Gatos Creek, where it drains into Lexington Reservoir, provided one hearty meal.

In addition, researchers’ cameras have captured glimpses of social behaviors between these creatures. They found one special site, where the region’s three females come to breed. The site lies right between the ranges of two males.

“It’s a hotspot,” said Wilmers, admiring a rare photo of a cluster of cats, all sharing a dead deer. “They’re usually such solitary creatures.”

Contact Lisa M. Krieger at 408-920-5565.

More about the Puma Project

UCSC is collaborating with the Felidae Conservation Fund and the California Department of Fish & Game on the project, with additional support from California State Parks. To contribute or read updates, go to www.felidaefund.org/research/bay_puma.html or call 415-889-5522.

Lisa M. Krieger is a science writer at The Mercury News, covering research, scientific policy and environmental news from Stanford University, the University of California, NASA-Ames, U.S. Geological Survey and other Bay Area-based research facilities. Lisa also contributes to the Videography team. She graduated from Duke University with a degree in biology. Outside of work, she enjoys photography, backpacking, swimming and bird-watching.

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